silvea

iTrader: (1)

Soo from what I've always been told the easiest way to tell the difference between a 4.8 and a 5.3 is the piston. The 4.8 are flat tops and the 5.3 have a dish. I've checked out a few engines and seen countless others where they advertise a 5.3. However when you get there the have it disassembled with the heads off to show you how clean it is and the cylinder walls are in good condition. Which is fine however they all have been flat top 4.8's. So either I'm wrong on the piston design (which I've looked up a few times and all state what I stated before) or people are selling a lot of 4.8's stating they are 5.3. Further it's hard to tell if it's people who got screwed and don't know it's a 4.8 not a 5.3 or just a lot of liars trying to make more money off their 4.8. Weird part is I've actually had a hell of a time finding a true 5.3 which I thought was a much more plentiful engine as I thought the 4.8 was a semi rare engine. Of all of the V8 Chevys I know with base engines they are all 5.3 engines only knowing 2 guys with 4.8 trucks because they were super cheap. #endrant

oChristiano

iTrader: (6)

Depends on Generation. Gen 4 5.3's do have flat tops. The dish vs flat top is only for Gen 3.

silvea

iTrader: (1)

So what's the difference between gen 4 5.3 and 4.8

Drewstein

I would say .5

NORCALMUSCLE1

iTrader: (9)

Also a Good tip is GM marked the blocked with either White Or yellow marking marking the block if it's a 4.8/5.3 , I just learned that when a buddy got a motor from a crashed truck at he's buddies tow yard,

1FastBrick

iTrader: (16)

That's not true. Its just a mark they use when checking blocks on the assembly line.

I have seen some with the 4.8 that were 5.3 and vica versa.

Pistons are the easy way to tell. On an Iron block flat tops are a 4.8L and dish is 5.3L

If not pull the pan and check the crank casting number.
4.8L = 12553482
5.3L = 12552216

A gen IV block has the knock sensors removed from the top and there are towers inside the block for DOD. Some of the blocks have Gen IV cast into them as well under the 4.8/5.3L logo. There is also no provision for a cam sensor on the block as it was moved to the front timing chain cover.